Adding social sharing buttons to posts

Hi again,
I’m wondering how I can add my social sharing buttons to my theme so that they automatically appear above every post.
I’ve been adding them to each post I write – see here: http://www.lovelightandlessons.com/3600/raw-orange-chocolate-slice-gluten-free-dairy-free-paleo/ – so four columns with the four sharing buttons as you can see, but I would like to be able to add them to the code so that they’re always there.
Can you advise me how to do this?

Thanks